Microstructure of CuFeS_2–δ–CuInS₂ alloys

Two series of alloys of the (CuFeS_2–δ)_1–x(CuInS₂)_x system with molar part of CuInS₂ x = 0.01, 0.03, 0.125, 0.25, 0.375, 0.50, 0.625, 0.75, 0.95, 0.97 and 0.99 and δ being 0 and 0.10 were prepared from the CuFeS_2–δ and CuInS₂ starting ternary compounds. The samples were investigated by micro structural optics using freshly-polished samples and XRPD. The studies confirmed two phase coexistences with microstructures dependent on the chemical composition. The geometric-oriented arrangement of the α-phase with the structure of CuInS₂ is found in the (CuFeS_2–δ)_1–x(CuInS₂)_x system up to x equalling 0.50. It was established that the solvus of CuFeS_2–δ exceeds 0.05 molar parts of CuInS₂, while the solvus of CuInS₂ does not exceed 0.03 molar parts of CuFeS_2–δ. Additionally, stoichiometric composition of CuFeS₂ exhibits a mixture of 3 coexisting phases of CuFeS_2–δ, with δ from 0.14 to 0.28, bornite Cu₅FeS₄ and pyrrhotite Fe_1–xS. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)